With the growth in wireless communications, the Federal Communication Commission has recently adopted rules to allow commercial shared use of 150 MHz of the 3.5 GHz band. Traditionally, this spectrum has been reserved for various Federal incumbent services, e.g., Department of Defense and fixed satellite services. Due to the nature of the Federal Incumbent services, much of this spectrum goes unused a large part of the time.
Under the new rules, the spectrum will be shared between the incumbent Federal services, and licensed and unlicensed users. The licensed and unlicensed users will not be allowed to interfere with the use of the spectrum by the Federal incumbent services. Under this paradigm, the licensed and unlicensed users must provide specified levels of protection from interference to Federal incumbent users. To this end, it is desirable to develop a technique to detect signals from Federal Incumbent users so that protection can be provided from interference.